diff options
8 files changed, 233 insertions, 25 deletions
diff --git a/compiler/rustc_mir_build/messages.ftl b/compiler/rustc_mir_build/messages.ftl index 32711c23dc4..563851f712c 100644 --- a/compiler/rustc_mir_build/messages.ftl +++ b/compiler/rustc_mir_build/messages.ftl @@ -221,6 +221,11 @@ mir_build_non_exhaustive_omitted_pattern = some variants are not matched explici .help = ensure that all variants are matched explicitly by adding the suggested match arms .note = the matched value is of type `{$scrut_ty}` and the `non_exhaustive_omitted_patterns` attribute was found +mir_build_non_exhaustive_omitted_pattern_lint_on_arm = the lint level must be set on the whole match + .help = it no longer has any effect to set the lint level on an individual match arm + .label = remove this attribute + .suggestion = set the lint level on the whole match + mir_build_non_exhaustive_patterns_type_not_empty = non-exhaustive patterns: type `{$ty}` is non-empty .def_note = `{$peeled_ty}` defined here .type_note = the matched value is of type `{$ty}` diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs index 5bfce3ab510..c4eed5532ee 100644 --- a/compiler/rustc_mir_build/src/errors.rs +++ b/compiler/rustc_mir_build/src/errors.rs @@ -789,6 +789,18 @@ pub(crate) struct NonExhaustiveOmittedPattern<'tcx> { pub uncovered: Uncovered<'tcx>, } +#[derive(LintDiagnostic)] +#[diag(mir_build_non_exhaustive_omitted_pattern_lint_on_arm)] +#[help] +pub(crate) struct NonExhaustiveOmittedPatternLintOnArm { + #[label] + pub lint_span: Span, + #[suggestion(code = "#[{lint_level}({lint_name})]\n", applicability = "maybe-incorrect")] + pub suggest_lint_on_match: Option<Span>, + pub lint_level: &'static str, + pub lint_name: &'static str, +} + #[derive(Subdiagnostic)] #[label(mir_build_uncovered)] pub(crate) struct Uncovered<'tcx> { diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs index 165d3f37111..8c3d09c19a1 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -285,7 +285,11 @@ impl<'thir, 'p, 'tcx> MatchVisitor<'thir, 'p, 'tcx> { } } - fn new_cx(&self, refutability: RefutableFlag) -> MatchCheckCtxt<'p, 'tcx> { + fn new_cx( + &self, + refutability: RefutableFlag, + match_span: Option<Span>, + ) -> MatchCheckCtxt<'p, 'tcx> { let refutable = match refutability { Irrefutable => false, Refutable => true, @@ -295,6 +299,7 @@ impl<'thir, 'p, 'tcx> MatchVisitor<'thir, 'p, 'tcx> { param_env: self.param_env, module: self.tcx.parent_module(self.lint_level).to_def_id(), pattern_arena: &self.pattern_arena, + match_span, refutable, } } @@ -325,7 +330,7 @@ impl<'thir, 'p, 'tcx> MatchVisitor<'thir, 'p, 'tcx> { source: hir::MatchSource, expr_span: Span, ) { - let cx = self.new_cx(Refutable); + let cx = self.new_cx(Refutable, Some(expr_span)); let mut tarms = Vec::with_capacity(arms.len()); for &arm in arms { @@ -448,7 +453,7 @@ impl<'thir, 'p, 'tcx> MatchVisitor<'thir, 'p, 'tcx> { pat: &Pat<'tcx>, refutability: RefutableFlag, ) -> Result<(MatchCheckCtxt<'p, 'tcx>, UsefulnessReport<'p, 'tcx>), ErrorGuaranteed> { - let cx = self.new_cx(refutability); + let cx = self.new_cx(refutability, None); let pat = self.lower_pattern(&cx, pat)?; let arms = [MatchArm { pat, hir_id: self.lint_level, has_guard: false }]; let report = compute_match_usefulness(&cx, &arms, self.lint_level, pat.ty(), pat.span()); diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index 1eb1dd72a61..da7b6587a72 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -311,7 +311,10 @@ use super::deconstruct_pat::{ Constructor, ConstructorSet, DeconstructedPat, IntRange, MaybeInfiniteInt, SplitConstructorSet, WitnessPat, }; -use crate::errors::{NonExhaustiveOmittedPattern, Overlap, OverlappingRangeEndpoints, Uncovered}; +use crate::errors::{ + NonExhaustiveOmittedPattern, NonExhaustiveOmittedPatternLintOnArm, Overlap, + OverlappingRangeEndpoints, Uncovered, +}; use rustc_data_structures::captures::Captures; @@ -337,6 +340,8 @@ pub(crate) struct MatchCheckCtxt<'p, 'tcx> { pub(crate) module: DefId, pub(crate) param_env: ty::ParamEnv<'tcx>, pub(crate) pattern_arena: &'p TypedArena<DeconstructedPat<'p, 'tcx>>, + /// The span of the whole match, if applicable. + pub(crate) match_span: Option<Span>, /// Only produce `NON_EXHAUSTIVE_OMITTED_PATTERNS` lint on refutable patterns. pub(crate) refutable: bool, } @@ -1149,28 +1154,50 @@ pub(crate) fn compute_match_usefulness<'p, 'tcx>( // Run the non_exhaustive_omitted_patterns lint. Only run on refutable patterns to avoid hitting // `if let`s. Only run if the match is exhaustive otherwise the error is redundant. - if cx.refutable - && non_exhaustiveness_witnesses.is_empty() - && !matches!( + if cx.refutable && non_exhaustiveness_witnesses.is_empty() { + if !matches!( cx.tcx.lint_level_at_node(NON_EXHAUSTIVE_OMITTED_PATTERNS, lint_root).0, rustc_session::lint::Level::Allow - ) - { - let witnesses = collect_nonexhaustive_missing_variants(cx, &pat_column); - if !witnesses.is_empty() { - // Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns` - // is not exhaustive enough. - // - // NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`. - cx.tcx.emit_spanned_lint( - NON_EXHAUSTIVE_OMITTED_PATTERNS, - lint_root, - scrut_span, - NonExhaustiveOmittedPattern { - scrut_ty, - uncovered: Uncovered::new(scrut_span, cx, witnesses), - }, - ); + ) { + let witnesses = collect_nonexhaustive_missing_variants(cx, &pat_column); + + if !witnesses.is_empty() { + // Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns` + // is not exhaustive enough. + // + // NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`. + cx.tcx.emit_spanned_lint( + NON_EXHAUSTIVE_OMITTED_PATTERNS, + lint_root, + scrut_span, + NonExhaustiveOmittedPattern { + scrut_ty, + uncovered: Uncovered::new(scrut_span, cx, witnesses), + }, + ); + } + } else { + // We used to allow putting the `#[allow(non_exhaustive_omitted_patterns)]` on a match + // arm. This no longer makes sense so we warn users, to avoid silently breaking their + // usage of the lint. + for arm in arms { + let (lint_level, lint_level_source) = + cx.tcx.lint_level_at_node(NON_EXHAUSTIVE_OMITTED_PATTERNS, arm.hir_id); + if !matches!(lint_level, rustc_session::lint::Level::Allow) { + let decorator = NonExhaustiveOmittedPatternLintOnArm { + lint_span: lint_level_source.span(), + suggest_lint_on_match: cx.match_span.map(|span| span.shrink_to_lo()), + lint_level: lint_level.as_str(), + lint_name: "non_exhaustive_omitted_patterns", + }; + + use rustc_errors::DecorateLint; + let mut err = cx.tcx.sess.struct_span_warn(arm.pat.span(), ""); + err.set_primary_message(decorator.msg()); + decorator.decorate_lint(&mut err); + err.emit(); + } + } } } diff --git a/src/tools/clippy/tests/ui/match_same_arms_non_exhaustive.rs b/src/tools/clippy/tests/ui/match_same_arms_non_exhaustive.rs index e1b95aa5776..5c277f925a8 100644 --- a/src/tools/clippy/tests/ui/match_same_arms_non_exhaustive.rs +++ b/src/tools/clippy/tests/ui/match_same_arms_non_exhaustive.rs @@ -9,12 +9,12 @@ fn repeat() -> ! { } pub fn f(x: Ordering) { + #[deny(non_exhaustive_omitted_patterns)] match x { Ordering::Relaxed => println!("relaxed"), Ordering::Release => println!("release"), Ordering::Acquire => println!("acquire"), Ordering::AcqRel | Ordering::SeqCst => repeat(), - #[deny(non_exhaustive_omitted_patterns)] _ => repeat(), } } diff --git a/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.lint.stderr b/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.lint.stderr new file mode 100644 index 00000000000..9192c66143c --- /dev/null +++ b/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.lint.stderr @@ -0,0 +1,75 @@ +error: some variants are not matched explicitly + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:15:11 + | +LL | match val { + | ^^^ pattern `NonExhaustiveEnum::Struct { .. }` not covered + | + = help: ensure that all variants are matched explicitly by adding the suggested match arms + = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found +note: the lint level is defined here + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:14:12 + | +LL | #[deny(non_exhaustive_omitted_patterns)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: some variants are not matched explicitly + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:23:11 + | +LL | match val { + | ^^^ pattern `NonExhaustiveEnum::Struct { .. }` not covered + | + = help: ensure that all variants are matched explicitly by adding the suggested match arms + = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found +note: the lint level is defined here + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:22:27 + | +LL | #[cfg_attr(lint, deny(non_exhaustive_omitted_patterns))] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +warning: the lint level must be set on the whole match + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:34:9 + | +LL | #[deny(non_exhaustive_omitted_patterns)] + | ------------------------------- remove this attribute +LL | _ => {} + | ^ + | + = help: it no longer has any effect to set the lint level on an individual match arm +help: set the lint level on the whole match + | +LL + #[deny(non_exhaustive_omitted_patterns)] +LL | match val { + | + +warning: the lint level must be set on the whole match + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:42:9 + | +LL | #[cfg_attr(lint, deny(non_exhaustive_omitted_patterns))] + | ------------------------------- remove this attribute +LL | _ => {} + | ^ + | + = help: it no longer has any effect to set the lint level on an individual match arm +help: set the lint level on the whole match + | +LL + #[deny(non_exhaustive_omitted_patterns)] +LL | match val { + | + +warning: the lint level must be set on the whole match + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:50:9 + | +LL | #[cfg_attr(lint, warn(non_exhaustive_omitted_patterns))] + | ------------------------------- remove this attribute +LL | _ => {} + | ^ + | + = help: it no longer has any effect to set the lint level on an individual match arm +help: set the lint level on the whole match + | +LL + #[warn(non_exhaustive_omitted_patterns)] +LL | match val { + | + +error: aborting due to 2 previous errors; 3 warnings emitted + diff --git a/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.normal.stderr b/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.normal.stderr new file mode 100644 index 00000000000..46093eb9fb3 --- /dev/null +++ b/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.normal.stderr @@ -0,0 +1,31 @@ +error: some variants are not matched explicitly + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:15:11 + | +LL | match val { + | ^^^ pattern `NonExhaustiveEnum::Struct { .. }` not covered + | + = help: ensure that all variants are matched explicitly by adding the suggested match arms + = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found +note: the lint level is defined here + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:14:12 + | +LL | #[deny(non_exhaustive_omitted_patterns)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +warning: the lint level must be set on the whole match + --> $DIR/omitted-patterns-dont-lint-on-arm.rs:34:9 + | +LL | #[deny(non_exhaustive_omitted_patterns)] + | ------------------------------- remove this attribute +LL | _ => {} + | ^ + | + = help: it no longer has any effect to set the lint level on an individual match arm +help: set the lint level on the whole match + | +LL + #[deny(non_exhaustive_omitted_patterns)] +LL | match val { + | + +error: aborting due to previous error; 1 warning emitted + diff --git a/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.rs b/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.rs new file mode 100644 index 00000000000..33f9f56a5bb --- /dev/null +++ b/tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns-dont-lint-on-arm.rs @@ -0,0 +1,53 @@ +// revisions: normal lint +// Test that putting the lint level on a match arm emits a warning, as this was previously +// meaningful and is no longer. +#![feature(non_exhaustive_omitted_patterns_lint)] + +// aux-build:enums.rs +extern crate enums; + +use enums::NonExhaustiveEnum; + +fn main() { + let val = NonExhaustiveEnum::Unit; + + #[deny(non_exhaustive_omitted_patterns)] + match val { + //~^ ERROR some variants are not matched explicitly + NonExhaustiveEnum::Unit => {} + NonExhaustiveEnum::Tuple(_) => {} + _ => {} + } + + #[cfg_attr(lint, deny(non_exhaustive_omitted_patterns))] + match val { + //[lint]~^ ERROR some variants are not matched explicitly + NonExhaustiveEnum::Unit => {} + NonExhaustiveEnum::Tuple(_) => {} + _ => {} + } + + match val { + NonExhaustiveEnum::Unit => {} + NonExhaustiveEnum::Tuple(_) => {} + #[deny(non_exhaustive_omitted_patterns)] + _ => {} + } + //~^^ WARN lint level must be set on the whole match + + match val { + NonExhaustiveEnum::Unit => {} + NonExhaustiveEnum::Tuple(_) => {} + #[cfg_attr(lint, deny(non_exhaustive_omitted_patterns))] + _ => {} + } + //[lint]~^^ WARN lint level must be set on the whole match + + match val { + NonExhaustiveEnum::Unit => {} + NonExhaustiveEnum::Tuple(_) => {} + #[cfg_attr(lint, warn(non_exhaustive_omitted_patterns))] + _ => {} + } + //[lint]~^^ WARN lint level must be set on the whole match +} |